Seam between two perfectly spliced meshes

Hi folks,
I’m new to this forum and I’m not sure if I chose the right category for my question. If not, I apologize.
This question has been bugging me and my team for a few days now, we’re looking to create a modular character - head and body in two parts, so that we can replace a different head model for a character to create a different look, and the body model can be reused.
However, we found that there is a conspicuous seam at the neck joint, such a seam does not appear in blender. We think this is a lighting issue but don’t know how to solve it, because when I changed the view mode to “no lighting”, the seam disappeared. Turning off the “cast shadows” option for the light source doesn’t help.
We also noticed a seam in the character’s UV joints, which is also not visible in “no lighting” mode.
Any ideas or advice would be appreciated.
Thanks in advance.

In Blender:

In Unreal Engine 5.2:
3

Disable lighting, it looks fine:
5

I think it’s because of the normals at the joint.

You can rewrite the normals in blender using a data transfer modifier.

You’ll need a cylinder ( or whatever shape the neck would be if it wasn’t cut ) position in exactly the same spot to use as a reference.

Not exactly the right vid, but something along these lines.

Thanks for your help. We tried your suggestion and found that there were some problems with the normals. We rewrote the normals and it worked. Thank you.

1 Like